/*const getSum = (a:number, b:number):number => {
    return a + b
}*/


type getSumFnType = (a: number, b: number) => number

const getSum: getSumFnType = (a: number, b: number): number => {
    return a + b
}
const result: number = getSum(10, 20)
console.log(result)


const fun: (a?: string) => void = (a?: string): void => {
    console.log("fun函数执行了")
}
fun()
